Many non-conductive or low conductivity containers have one or more coating materials applied to their outer surface. These coatings may be used as a protective layer, for example. In the past, coatings have been applied using an electrostatic process. In the case of glass bottles, for example, a metal pin has been inserted into a bottle opening with a dielectric separation between the metal pin and the bottle. Metal parts in electrostatic coating systems may allow unwanted capacitive discharges, sometimes creating a safety hazard.
During electrostatic coating operations on non-conductive and low conductivity work pieces such as glass bottles, the electrostatic process may build up electrostatic charge on the bottle which may act in effect like a capacitor because the container may not effectively be grounded. This charge build up can have deleterious effects on the overall finish and transfer efficiency. Thus, low conductivity containers may become self-limiting as to how much electrostatic charge can be applied to the container during an electrostatic coating operation. The build-up of coating material on the container during a coating operation may further limit the coating process.